Derby Talk

Derby Talk is a forum for Pinewood Derby, Awana Grand Prix, Kub Kar Rally, Shape N Race Derby, Space Derby, Raingutter Regatta and other similar races where a child and an adult work together to create a race vehicle and a lot of fun and memories

Darin McGrew wrote:But it doesn't always look like that when I'm reading threads like this one.

Is your concern with the idea of considering a different rule set that de-emphasizes design aspects that require expensive materials in order be competitive? Or something in the responses to the idea?

I think your proposed wheelbase rule is perfectly reasonable. It seems just as enforceable as any other wheelbase rule, and the stated rationale makes sense, de-emphasizing "buying the right stuff" in favor of "doing the right stuff".

FatSebastian wrote:Personally, I refuse to salvage previously raced cars as a matter of principle: having competed, the car becomes the child's trophy and it is not mine to suggest dismantling. I respect that others have different feelings, but I also know that we are not alone in this approach. We resisted using tungsten for a long time because of its cost even when we had our own (cheap homemade) practice track; when one is unwilling to recycle, tungsten gets particularly expensive if one has several children competing at the same time.

Understood. I have 8 kids, so I know that all too well. We ran 5 cars this year, all with Tungsten.

I think a piece that you are missing is the fact that many scouts just buy the kit and stick the axles right out of the box into the supplied slots. I don't think this could be done with your rule could it?

resullivan wrote:I think a piece that you are missing is the fact that many scouts just buy the kit and stick the axles right out of the box into the supplied slots. I don't think this could be done with your rule could it?

Why not? Are the original slots further than 6in from the opposite end?

resullivan wrote:I don't think this could be done with your rule could it?

Based on this early response from Stan, it appears that his intention was always to specify the dimension so that the original slots could be used (whatever that number is - probably 6-1/16" per ah8tk and 5 J's).

As an addition to this post, our current district race requires the 4 3/8 wheelbase but allows drilling. I was thinking of removing this requirement to encourage greater attendance. I understand this would attract more sophisticiated builders which I think is OK but my concern is that the district race will die if we dont have a good showing. I would rather have a district race of sophisticated builders and pack champs than no race. I assume that even a sophisticated builder would be discouraged about having to make a second stock wheelbase car after making a pack extended wheelbase car.

As of now our district is unlimited allowing any and all district scouts and siblings. One would think we would have a landslide of scouts but as the cubmaster for my pack I have been pushing the race and dont have anyone interested in going. We are the second largest pack in the district.

In terms of what percent of pack run pack races-dont know but I now have all the cubmaster's e-mail addresses and will be polling.

As of now our district is unlimited allowing any and all district scouts and siblings. One would think we would have a landslide of scouts but as the cubmaster for my pack I have been pushing the race and dont have anyone interested in going. We are the second largest pack in the district.

Noskills

Not uncommon! The district race can be viewed as a Cub event open to everyone, or as a reward for doing well in the pack races. As a reward, it increases the value of doing well in the pack races and adds to the excitement there. If too few can earn the reward, then your event participation suffers. Often not recognized, however, is that if too many (e.g. all) can earn the reward, then event participation also suffers because it ceases to be a reward.

By doing well in your pack race, those who qualify (3 or 4 per grade per pack) are representing your pack. If the pack pays their registration, then there is even more motivation to participate!

By limiting participation to 4 per grade per pack and promoting the district PWD that way in your Cub Scout Roundtable meetings, you should be able to average at least 10 boys per pack.

Stan Pope wrote:By limiting participation to 4 per grade per pack and promoting the district PWD that way in your Cub Scout Roundtable meetings, you should be able to average at least 10 boys per pack.

This, however, may create a brand new problem: How do you run a fun event when you have 60 to 100 boys competing in each class? If, for instance, you have 60 entries per class, Bear for instance, and you are able to run 1 heat per minute on a 3-lane track, then each scout will race, on average 3 times per hour. That is a lot of waiting for just a little action!

The most satisfactory solution I've seen is the 15th Burlington method which employs multiple tracks to sort out the fastest dozen or so who then participate in "finals", a conventional timed race of 3 to 6 heats per racer. For most of the time, all participants are racing frequently, typically 12 to 15 times per hour. And the finals for one group can overlap with the multi-track racing of the next group!

Stan,
A car dimension thought!
If rules on the car dimensions state that the overall length of the car shall not exceed 7'' inches
Whats to keep someone from building a smaller wheel base car thats even shorter
then overall length given in the rules?

I here alot of complaining about the ext-wheel base cars in the kids events.
but no one ever gripes about the shorter length or even shorter wheel base cars.

Last edited by whodathunkit on Sun Apr 27, 2014 4:57 pm, edited 1 time in total.

With Stan's proposed rule, a shorter car could get the wheels closer to the ends of the car. But a shorter car or a shorter wheelbase isn't really an advantage, so I don't see this creating problems.

Of course, if someone builds a shorter car that is also really fast (fast enough to win the district/council race), then the fact that a shorter car doesn't have an advantage won't stop people from crying foul...

whodathunkit wrote:Stan,
A car dimension thought!
If rules on the car dimensions state that the overall length of the car shall not exceed 7'' inches
Whats to keep someone from building a smaller wheel base car thats even shorter
then overall length given in the rules?

I here alot of complaneing about the ext-wheel base cars in the kids events.
but no one ever grips about the shorter lenght or even shorter wheel base cars.

The reason that few complain is that a short wheelbase, dictated by a short body, confers no energy advantage. It is, in fact, a disadvantage.

I believe (yet to prove) that a short wheelbase on a full size body ... when the rear axles are at the rearmost legal location ... may be advantageous. The reason is that such a configuration allows more rearward CM location without making the frontend too light AND, as a result, allows less DFW toe-in to hold the line.

If rules dictate the stock wheelbase be used ( 4 3/8" ) and the wheelbase is shifted toward the rear (cut off the back 1/4" and move it to the front) that gives an advantage regarding the Front End Extension Effect and a Higher Velocity. If the CM's of a stock block and a block with a shifted wheelbase are lined up when they reach the horizontal run (Cycloid of Constant Time) the shifted wheelbase car is a head of the stock wheelbase car and has a higher velocity. The CM on the shifted wheelbase car will travel a lesser distance then the CM on the stock block. Between 2 perfect cars the shifted wheelbase car would have to win. I think a short wheelbase on a full size body, when the rear axles are at the rearmost legal location, has to be an advantage Per the Laws of Physics. This is what I understood from Doc Jobe, Page 40 of the Green Book and is why I always shift the wheelbase. Our rules do not prohibit this. However, if Stan's rule was implemented this would no longer be legal.